Microprocessor technology has opened new potential in biomedical engineering for a new class of instrumentation. Complex data processing and control tasks may now be performed in individual instruments while at the same time simplifying man-machine interaction. Effective application of microprocessor technology to clinical instrumentation requires a critical mass of expertise and equipment. The Biomedical Engineering Center for Clinical Instrumentation has assembled the required medical and engineering expertise and technology to effectively employ the power of microprocessors in solving important clinical instrumentation problems. The Center consists of a core Microprocessor Engineering Laboratory (MEL) located on the MIT campus, and project sites at various clinical facilities - usually teaching hospitals. The MEL has created a powerful, flexible base of hardware and software to support the development of microprocessor-based clinical instruments. Four specific instrument systems will enter intense clinical evaluation in the next three years. In addition, three new projects will be added to the Center. The MEL will provide engineering support to the new projects. In addition, the MEL will provide resources for the maintenance and modification of instruments undergoing clinical trials.